Alumina Ceramics Vacuum Duct for the 3GeV-RCS of the J-PARC

It was success to develop alumina ceramics vacuum ducts for the 3GeV-RCS of J-PARC at JAERI. This duct has titanium flanges and exterior RF shield to reduce duct impedance. The longitudinal duct impedance was sufficient small for stable beam acceleration from impedance measurement by coaxial method. The temperature of titanium flange became 45 Co due to eddy current heating under dipole magnet operation. This duct is usable for the 3GeV-RCS of J-PARC.